Cable network device having interconnected microstrip directional couplers

Abstract

There is provided a cable network device comprising an input associated with a plurality of outputs, wherein each output is connected to a respective microstrip directional coupler and each microstrip directional coupler is connected to at least one of the other microstrip directional couplers. The microstrip directional couplers form a series of microstrip directional couplers, with a last microstrip directional coupler in the series having its output port terminated by a resistive element. An isolated port of each microstrip directional coupler is in electrical communication with the upstream path.

What is claimed is: 
     
       1. A cable network device, comprising:
 an input associated with a plurality of outputs, each output connected to one of a series of interconnected microstrip directional couplers, and configured with separate upstream and downstream paths; 
 a first transformer located in the upstream path; and 
 a second transformer, 
 wherein an isolated port of each microstrip directional coupler is in electrical communication with the upstream path and the isolated port of alternate microstrip directional couplers in the series is connected to the isolated port of one adjacent microstrip directional coupler using the second transformer. 
 
     
     
       2. The cable network device according to  claim 1 , wherein each connected pair of isolated ports is connected to the adjacent connected pair of isolated ports using at least one transformer. 
     
     
       3. The cable network device according to  claim 1 , wherein each microstrip directional coupler in the series is connected to an adjacent microstrip directional coupler by connecting an output port of a first microstrip directional coupler in the series to an input port of the next microstrip directional coupler in the series. 
     
     
       4. The cable network device according to  claim 3 , wherein a last microstrip directional coupler in the series has its output port terminated by a resistive element. 
     
     
       5. The cable network device according to  claim 4 , wherein each output is connected to a coupled port of its respective microstrip directional coupler. 
     
     
       6. The cable network device according to  claim 1 , wherein a phase inverting transformer is disposed between the input and each microstrip directional coupler output port. 
     
     
       7. The cable network device according to  claim 1  being an amplifier.